投 throw

Use your hand to throw a ball at the umpire's TOE

vote ★★★☆☆
投 (throw) + 票 (ballot) = 投票 (vote)

to vote (also, it can mean election, as in "Did he win the vote?")

contribute ★☆☆☆☆
投 (throw) + 書 (write) = 投書 (contribute)

contribute to a magazine - letter to the editor, purikura, etc.